What do I do if I can't stop thinking about her?

Me and this girl met at a party on Saturday and we really hit it off. We talked and were both generally tipsy. She did some stuff to me, I did some stuff to her. It was a good night. At the end she gave me her number and told me to text her. And this is when it kinda started, as soon as I got home I started thinking about her. Now its snowballed into me losing some sleep over it. She asked me if I was trying to make it into something (relationship) over text. I told her that I am if you are. She's not sure because she can't do it without hurting this other guy that's taking her to his prom in 2 weeks. I'm getting the vibe that she likes me more, because of the events that took place. But I want it to become something. I can't stop thinking about her, I want to text her, call her and spend time with her. I really don't know what this is. Please help.